The National Weather Service (NWS) and its hydrological division, the River Forecast Centers (RFC), collect precipitation accumulation data from a nationwide network of sampling stations. The NWS employs a sophisticated network of automated surface rainfall gauges and human observers, along with radar and satellite estimating techniques to derive highly accurate measurements of rainfall data from across the continental United States (“CONUS”).
Similarly, the NWS' National Operational Hydrologic Remote Sensing Center (“NOHRSC”) collects snowfall data from a variety of comprehensive sources including, for example, satellites, airborne platforms, and ground stations. The NOHRSC combines the data from these various sources to create snow precipitation measurements.
The NWS precipitation data is highly accurate and provides high resolution estimates of precipitation. The high fidelity of the data is the result not only of the sophisticated techniques that are used to collect the data, but also of the extensive data processing and quality control processing that takes place after the data is collected and prior to the data being released to the public. Data collected by the NWS typically undergoes extensive manual quality control procedures and is subject to automated collation, filtering, and mosaicing. This processing is intensive and often time consuming, resulting in several hours of delay between the time data is collected and when data is prepared for release to the public. For example, the NWS precipitation data that is eventually released to the public may be based on precipitation measurements taken 12 to 36 hours earlier. As a consequence, when NWS precipitation data is made available to the public, which generally takes place only once daily, the data may not reflect precipitation and/or snow that has fallen within the hours just prior to when the data is released to the public.
Precipitation data may be gathered from sources other than the NWS. For example, the High-Resolution Real-Time Synthetic Meteorological Conditions from Radar Data (“HIRAD”) system described in U.S. Pat. No. 7,231,300, the contents of which are hereby incorporated by reference in their entirety, provides weather condition information, including, for example, precipitation data. The accuracy of the data from systems such as HIRAD is generally considered to be less than that offered by the NWS systems. However, in systems such as HIRAD, precipitation measurement data may be made available at relatively frequent intervals as compared to the data provided by the NWS. For example, weather condition information such as precipitation accumulation data may be made available, for example, every 20 minutes.
Thus, while precipitation data from the NWS is accurate and provides high resolution, the data may be delayed and may not reflect precipitation that has fallen in the immediate past. Precipitation data from other sources, such as, for example, HIRAD, may not be of the same quality as the NWS data, but the data is more immediately available and reflects recent precipitation.